A congressional report says the Chinese government likely illegally entered computers of an American federal agency. The Federal Deposit Insurance Corporation, or FDIC, supervises banks. The report says employees of the agency hid news about the computer attacks -- which took place in 2010, 2011 and 2013 -- to protect the head of the agency.

The report noted that an FDIC investigation said the Chinese government was probably responsible for the attacks. Congressional investigators said the attacks were hidden to protect Martin Gruenberg, who was named to lead the agency in 2011.

Lamar Smith is a Republican member of the House of Representatives from Texas. He is the chairman of the House Committee on Science, Space and Technology.

He said the committee’s report shows weaknesses in the FDIC’s computer security efforts. He also called the FDIC’s reported attempt to escape congressional supervision “a serious offense.” He said “there is a culture of concealment at the FDIC.”

There is growing concern about the openness of the international banking system to computer criminals. The attack of the FDIC computers could be an indication of how deeply China has illegally entered U.S. government computer networks. However, the congressional report did not give evidence that China was responsible.

Shane Shook is a computer security expert. He has investigated some of the attacks on U.S. government computers. He said the congressional report did not persuade him that the Chinese government hacked the FDIC.

“As with all government agencies, there are management issues stemmingfrom leadership ignorance of technology oversight,” Shook said.

In Beijing, a Chinese Foreign Ministry official said China opposes hacking and has taken actions against computer criminals.

“People should provide evidence for their accusations,” he said. He told reporters the U.S. government’s accusations against China were “extremely irresponsible.”

The FDIC holds secret information about the country’s largest banks and its customers. The FDIC did not answer press questions about the report.

But on Thursday, Gruenberg admitted to members of the committee that the agency had failed to protect important banking information. He said the agency’s computer security plans did not work. In Gruenberg’s words, “this is a serious matter that must be addressed so that it does not happen again.”

The U.S. has accused China of hacking several federal agencies. In one incident, American officials say, China stole more than 21 million computer records about former and current federal employees.

In May, the news media began reporting that a foreign government may have illegally entered the FDIC’s computer systems. Some lawmakers said at the time that China was a suspect.

In 2013 the FDIC’s top independent investigator identified China as the likely suspect. The new congressional report is the first public release of information about that finding.

The congressional report says “even the former Chairwoman’s computer had been hacked by a foreign government” -- likely the Chinese. Sheila Bair led the agency from 2006 until 2011, when Gruenberg was named temporary chairman.

The report says criminals illegally entered 12 FDIC computers. They include those of the former top assistant to the agency’s chairman and the agency’s former top lawyer. The congressional report also said 10 servers were hacked. Other reports say many more computers were illegally entered and the information of individual bank customers was stolen.

A witness told congressional investigators that a top FDIC official told workers not to report the hack to protect Gruenberg’s chances of being confirmed as chairman of the agency. On Thursday, Gruenberg told members of Congress that he did not know about any possible efforts to cover up reports about the hacks.